1. Field of the Invention
The present invention relates to a manufacturing apparatus and method, and more particularly, to an apparatus and method for manufacturing a liquid crystal display device suitable for a large-sized liquid crystal display.
2. Discussion of the Related Art
In general, recent developments in the information communication field have increased demand for various types of displays devices. In response to this demand, various flat panel type displays such as liquid crystal display (LCD), plasma display panel (PDP), electro-luminescent display (ELD), and vacuum fluorescent display (VFD) have been developed to replace conventional cathode ray tube (CRT) devices. In particular, LCD devices have been used because of their high resolution, light weight, thin profile, and low power consumption. In addition, LCD devices have been implemented in mobile devices such as monitors for notebook computers. Furthermore, LCD devices have been developed for monitors of computer and television to receive and display broadcasting signals.
Accordingly, efforts to improve image quality of LCD devices contrast with the benefits of high resolution, light weight, thin profile, and low power consumption. In order to incorporate LCD devices as a general image display, image quality such as fineness, brightness, large-sized area, for example, must be realized.
A plurality of gate lines are formed along one direction at fixed intervals on the first glass substrate (TFT array substrate), and a plurality of data lines are formed along a second direction perpendicular to one direction of the plurality of gate lines, thereby defining a plurality of pixel regions. Then, a plurality of pixel electrodes are formed in a matrix arrangement at the pixel regions, and a plurality of thin film transistors (TFT) are formed at the pixel regions. Accordingly, the plurality of thin film transistors are switched by signals transmitted along the gate lines and transfer signals transmitted along the data lines to each pixel electrode. In order to prevent light leakage, black matrix films are formed on the second glass substrate (color filter substrate) except at regions of the second glass substrate that correspond to the pixel regions of the first glass substrate.
A process for manufacturing an LCD device using a TFT substrate and a color filter substrate will be described with reference to a manufacturing apparatus according to the related art.
The process for manufacturing an LCD device according to the related art includes steps of forming a sealant pattern on one of a first and second substrate to form an injection inlet, bonding the first and second substrates to each other within a vacuum processing chamber, and injecting liquid crystal material through the injection inlet in the other vacuum chamber. In another process of manufacturing an LCD device according to the prior art, a liquid crystal dropping method, which is disclosed in Japanese Patent Application No. 11-089612 and 11-172903, includes steps of dropping liquid crystal material on a first substrate, arranging a second substrate over the first substrate, and moving the first and second substrates, thereby bonding the first and second substrates to each other. Compared to the liquid crystal injection method, the liquid crystal dropping method is advantageous in that various steps such as, formation of a liquid crystal material injection inlet, injection of the liquid crystal material, and sealing of the injection inlet are unnecessary since the liquid crystal material is predisposed on the first substrate.
FIGS. 1 and 2 show cross sectional views of a substrate bonding device using the liquid crystal dropping method according to the prior art. In FIG. 1, the substrate bonding device includes a frame 10, an upper stage 21, a lower stage 22, a sealant dispensor (not shown), a liquid crystal material dispenser 30, a processing chamber includes an upper chamber unit 31 and a lower chamber unit 32, a chamber moving system 40, and a stage moving system 50. The chamber moving system 40 includes a driving motor driven to selectively move the lower chamber unit 32 to a location at which the bonding process is carried out, or to a location at which outflow of the sealant occurs and dropping of the liquid crystal material. The stage moving system 50 includes another driving motor driven to selectively move the upper stage 21 along a vertical direction perpendicular to the upper and lower stages 21 and 22.
A process of manufacturing an LCD device using the substrate bonding apparatus according to the prior art follows. In FIG. 1 First, a second substrate 52 is placed upon the upper stage 21, and a first substrate 51 is placed upon the lower state 22. Then, the lower chamber unit 32 having the lower stage 22 is moved to a processing location (S1) by the chamber moving system 40 for sealant dispensing and liquid crystal material dispensing. In FIG. 2 Subsequently, the lower chamber unit 32 is moved to a processing location (S2) for substrate bonding by the chamber moving system 40. Thereafter, the upper and lower chamber units 31 and 32 are assembled together by the chamber moving system 40 to form a vacuum tight seal, and a pressure in the chamber is reduced by a vacuum generating system (not shown). Once a sufficient pressure is attained, the upper stage 21 is moved downwardly by the stage moving system 50 to fasten the second substrate 52 to the first substrate 51, and a continuous pressurization of the chamber completes the manufacture of the LCD device.
Unfortunately, the substrate bonding apparatus according to the prior art is disadvantageous. First, the substrate bonding apparatus according the prior art fails to dispense sealant and liquid crystal material on a substrate on which thin film transistors and a color filter are formed. Second, an overall size of the bonding apparatus fails to allow for other processing, thereby making it difficult in designing a layout for a manufacturing process of a liquid crystal display device. Third, due to performing multiple processes using a lower chamber unit, processing time is greatly increased, thereby decreasing overall productivity. According to the prior art, the amount of time to dispense the sealant on the first substrate, to dispense the liquid crystal material on the second substrate, and to bond the first and second substrates, results in significant amounts of time in which all of the manufacturing processes are sequentially performed and completed. Fourth, if a vacuum tight connection between the upper and lower chamber units is not attained, airflow will occur between the upper and lower chamber units, thereby resulting in a poor bond between the first and second substrates. Accordingly, additional components for assuring a vacuum tight seal between the upper and lower chamber units is required. Finally, alignment of the first and second substrates during bonding is difficult because of horizontal movement of the lower chamber unit, thereby increasing overall processing time.